薄壁工件多点磁力辅助夹具设计研究

Research on Multi-Point Magnetic Auxiliary Fixture for Thin-Walled Workpieces

航空发动机叶片等薄壁工件是典型的弱刚性工件,具有壁厚薄、刚性差、型面复杂以及材料难加工等特点,在加工过程中极易产生弯曲、扭转变形导致工件超差。针对叶片类薄壁零件加工过程中弱刚性导致的变形及复杂曲面难以支撑问题,首先,对现有相变材料辅助夹具进行了分析,并提出了薄壁零件的无应力辅助支撑原理;然后,基于无应力辅助支撑原理及复杂曲面离散化原则设计了一种用于叶片类薄壁工件辅助支撑的多点磁力辅助夹具,并对其装夹变形以及辅助支撑能力进行了理论分析和试验研究;最后,基于该辅助支撑夹具对叶片进行了磨削加工试验,验证了所设计的辅助夹具在弱刚性工件刚性增强以及加工变形控制方面的优越性。

As typical thin-walled workpiece,aero-engine blades are weak-stiffness,complex surface and difficult processing materials which make it easily to deform during the machining process.To address the deformation caused by the weak-stiffness and difficult supporting of the complex surfaces during machining process,the existing phase change material auxiliary fixtures was firstly analyzed and a stress-free auxiliary support principle for thin-walled parts was proposed in this paper.Then,a multi-point magnetic auxiliary fixture for auxiliary support of blade-like thin-walled parts is designed based on the stress-free auxiliary support principle and the principle of discretization of complex surfaces.Furtherly,the clamping deformation and auxiliary support ability are theoretically analyzed and experimentally studied.Finally,a blade is machined with the designed auxiliary fixture and the results shows that the multi-point magnetic auxiliary fixture can enhance the rigidity of weakly rigid workpieces and reduce machining deformation significantly.